title: Combination treatment with high-dose vitamin C and alpha-tocopherol does not enhance respiratory-tract lining fluid vitamin C levels in asthmatics.
abstract: Oxidative stress plays a significant role in allergic airway inflammation. Supplementation with alpha-tocopherol (alone or combined with ascorbate/vitamin C) has been assessed as an intervention for allergic airway diseases with conflicting results. Enhancing levels of airway antioxidants with oral supplements has been suggested as an intervention to protect individuals from the effect of inhaled oxidants, although it is unclear whether supplementation changes tocopherol or vitamin C levels in both serum and airway fluids. Our objective was to obtain pilot safety and dosing data from 14 allergic asthmatic volunteers examining the effect of daily combination oral therapy with 500 mg alpha-tocopherol (alpha T) and 2 g vitamin C for 12 wk. We examined serum and airway fluid and cellular levels of alpha- and gamma-tocopherol (gamma T) and vitamin C to plan for future studies of these agents in asthma and allergic rhinitis. Six volunteers completed 12 wk of active treatment with alpha T and vitamin C and 8 completed placebo. Blood and sputum samples were obtained at baseline and at 6 wk and 12 wk of therapy and were analyzed for alpha T, gamma T, and vitamin C levels in the serum, sputum supernatant, and sputum cells. Combination treatment increased serum vitamin C and significantly decreased sputum alpha T and serum gamma T levels. No changes were found in sputum supernatant or sputum cell vitamin C or serum alpha T levels in the active treatment group. In conclusion, supplementation with alpha T and high-dose vitamin C does not augment vitamin C levels in the respiratory-tract lining fluid.
authors.affiliation: The Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina School of Medicine, 104 Mason Farm Road, Chapel Hill, NC 27599-7310, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Hernandez
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhou
authors.forename: Bingqing
authors.initials: B
authors.lastname: Zhou
authors.forename: Carole
authors.initials: C
authors.lastname: Robinette
authors.forename: Kay
authors.initials: K
authors.lastname: Crissman
authors.forename: Gary
authors.initials: G
authors.lastname: Hatch
authors.forename: Neil E
authors.initials: NE
authors.lastname: Alexis
authors.forename: David
authors.initials: D
authors.lastname: Peden
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D002214:Capsules; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D020545:Respiratory Mucosa / Q000737:chemistry* / Q000187:drug effects*; D044967:Serum / Q000737:chemistry; D013183:Sputum / Q000737:chemistry / Q000166:cytology; D014815:Vitamins / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry; D024504:gamma-Tocopherol / Q000097:blood / Q000737:chemistry
chemical_list: D002214:Capsules; D014815:Vitamins; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol; D001205:Ascorbic Acid